Subdued Fish

[tom_os]

all my fish in my 60l tank dont seem to be very active today.

i have 5 black phantom tetras, 1 pitbul pleco, 4 danios and 6 cories

the cories are just resting on the bottom, not digging around like they normally do. 1 danio is right at the surface but not heavily breating or anything. the others are down the bottom.

did my normal 40% weekly water change toady. added stress coat dechlorinator as usual.

ammonia: 0
nitrite:0
nitrate: 0 after w/c. normally about 30
ph: 7.8

nothing recently has been added, apart from the pitbull on thursday. but he seems fine and all the fish were fine before today

can anyone help

 

[Eines]

Do you have an air pump? Are the danios actually resting on the bottom or just floating closer to the bottom than usual? Are they still coming up to feed? If they're not lying on the bottom and are still eating, you may just have to wait it out a few days, since there don't seem to be any obvious signs of disease.

 

[WILDER]

Is there plenty of aeration in the tank.
Your tanks slightly overstocked.
Corys do rest on the bottom of the tank.